Finding names of his two daughters.
Have you tried looking on Passenger arrival records for their visit to USA.
There were fewer immigrants in the 1930's and you might get lucky.
VP of Membership, JGS of North Jersey
FREUND Pruchnik, FELDMAUS Lezajnsk
SULTAN, Husiatyn, GOLDBERG Mostiska
SALOMON, HIRSCH, THAL Neumagen, Germany